Question

multiple choice question
the upwelling of cold, nutrient - rich water off the coast of peru (south america) is weakened or shut down during the southern oscillation because

the net transport of water is offshore, limiting the upwelling of water from deeper waters

warm surface waters are pushed across the pacific and are pushed up against the coast

the deep waters are warmed and depleted in nutrients by the related el niño events

the high - pressure system holds the deep water down and prevents its upwelling

Explanation:

During the Southern Oscillation, especially during El - Niño events, warm surface waters are pushed across the Pacific and pile up against the coast of Peru. This blocks the normal upwelling of cold, nutrient - rich water from deeper levels.

Answer:

warm surface waters are pushed across the Pacific and are pushed up against the coast